Roll apparatus for localized embossing



y 1953 F. A. SUNDERHAUF ETAL 2,639,660

ROLL APPARATUS FOR LOCALIZED mossmc Filed Feb. 14, 1951 I T /wa PatentedMay 26, 1953 ROLL APPARATUS FOR LOCALIZED EMBOSSING Frederick A.Sunderhauf, Summit, and James C. OHear, Union, N. J.

Application February 14, 1951, Serial No. 210,886

3 Claims. 1

This invention relates to the art of roll embossing wherein a sheet ofmaterial is provided with an embossed or raised design by being passedbetween a pair of embossing rolls and, more particularly, to a novelmethod and apparatus for roll embossing only a localized area orlongitudinal portion of the sheet material.

Heretofore it was not feasible to roll emboss only a portion of acontinuous sheet of material. That is, the methds and apparatus of theprior art could be employed only for embossing the entire area of thesheet since past attempts to emboss solely localized areas of the sheetwould invariably result in the sheet being wrinkled, torn and otherwisedefective.

We have discovered that when it is attempted to employ conventionalembossing rolls for localized embossing, such wrinkles and distortionsoccur due to the fact that the embossing of the localized area causesthe latter to be elongated in a. direction along the path of travel ofthe sheet material whereas the remaining unembossed area of the sheetretains its original length.

It is, therefore, a primary object of the present invention to provide anovel method and apparatus for roll embossing solely localized areas orlongitudinal portions of the sheet to be embossed, wherein theunembossed areas of the sheet are reduced in thickness and elongatedsimultaneously with and to the same extent of the elongation that occursin the localized embossed area as a result of the embossing thereof,thereby preventing any difference in length between the embossed andunembossed areas of the sheet so as to avoid wrinkles, and otherdistortions therein. This novel and highly advantageous result enables,for the first time in the art of roll embossing, a sheet to be embossedat only a local longitudinal area or portion thereof since the wrinklesand other defects inherent in the prior art methods and apparatus wereso prevalent as to preclude, heretofore, the practice of localizedembossing by rolls.

This elongation of the unembossed area simultaneously with the embossingof the localized area is obtained by providing the rolls with rolling orreducing surface areas which roll the unembossed area of the sheettherebetween so as to reduce its thickness and thereby elongate theunembossed area in the direction of the path of travel of the sheet. Byexperiment the extent of elongation that the particular embossingoperation will produce in a given material of a certain thickness can bemeasured, and from this the desired elongation of the unembossed area 2and hence its desired reduction of thickness and also the properdistance between the rolling or reducing non-embossing surfaces of thetwo rolls can be determined.

Another important and novel feature of the present invention resides inthe discovery that considerably improved results are obtained bymaintaining a clearance space between the raised parts of the designembossed on the sheet and the bottoms and sides of the embossingrecesses in one of the embossing rolls. That is, the embossing recessesof one roll are formed deeper and wider than the corresponding embossingprojections on the other roll, whereby when the projections press partsor" the sheet into the recesses these parts remain out of contact withthe bottoms and sides of the recesses, thereby preventing gripping,tearing and distorting the embossed sheet area and also reducing wear onthe rolls when the latter are employed for embossing sheet metal.Furthermore, by maintaining the raised parts of the embossed design outof contact with one of the rolls, these parts are not Worked and henceretain their original color and texture, thereby providing the raisedparts with a dull surface contrasting with the relatively smooth, shinysurface of the non-raised parts of the embossed design, this contrastresulting in a distinctive pleasing appearance of the embossed sheet.

In the drawing wherein is illustrated one embodiment of the invention:

Fig. 1 is a perspective view of a pair of embossing rolls constructed inaccordance with the present invention and showing a sheet of materialbeing passed through the rolls so as to emboss only a localizedlongitudinal strip area of the sheet;

Fig. 2 is a sectional view of the sheet material before being passedthrough the embossing rolls and taken substantially on the line 22 ofFig. 1;

Fig. 3 is a transverse sectional view taken on a plane through the axesof the rolls as indicated by the line 3-3 of Fig. l, and shows to anexaggerated extent the clearance space between a raised or embossedportion of the sheet and the bottoms and sides of the correspondingembossing recess in the lower roll; and

Fig. 4 is a transverse sectional view of the embossed sheet after it haspassed through the rolls and taken on the line 4--4 of Fig. 1.

Referring first to Fig. l, the reference numerals I I, [2 indicate apair of embossing rolls which are rotatable mounted within an embossingapparatus (not shown). The manner of mounting the rolls and drivinglyrotating them is well known and need not be described, except to statethat the rolls ll, l2 are provided with gears l3, M which maintain themin proper synchronized angular orientation with respect to each other.The gears l 3, l4 may each be provided with an indicator mark as at X,these marks being brought into adjacent alignment whenever the rolls arebrought together after having been moved apart, whereby each element ofthe embossing surface of one roll will always co-act with the samecorresponding element on the embossing surface of the other roll.

The reference letter S indicates the work piece or sheet of materialwhich is to be passed between the rolls ii, I2 so as to undergo alocalized embossing operation. B localized embossing is meant theforming of an embossed or raised pattern or design on a longitudinalarear of the sheet S, the remaining area of the sheet S beingunembossed. More particularly, it will be seen in Fig. 1 that theleft-hand strip or area S of the sheet S remains unembossed afterpassing through the rolls ll, [2, the right-hand area S being subjectedto the localized embossing operation.

In order to perform this localized embossing operation on the right-handsheet area S", the exterior surfaces of the rolls H, 12 are providedwith embossing surfaces ii, H2" at their righthand portions, theremaining portions of the rolls H, [2 being devoid of embossingprojections or recesses. As best seen in Fig. 3, the embossing surfaceof the upper roll 9 I comprises a plurality of embossing projections l5,each of which co-acts with a corrresponding embossing recess it in theembossing surface of the lower roll 52, so as to raise or emboss aportion I? of the sheet S.

It should be noted that each of the embossing recesses i6 is wider anddeeper than its corresponding embossing projection Hi. This provides aclearance space between the raised portion ll of the sheet S and thebottoms and sides of the embossing recesses of one of the rolls, wherebygripping, tearing and distortion of the embossed sheet areas during theembossing operation is prevented. Furthermore, when the material of thesheet S is metal, this provision for clearance considerably reduces wearand breakdown of the rolls.

It will be noted that the surface ll of the raised portion ll of thesheet S remains out of contact with the lower roll !2, whereas theremaining portions of the sheet S contact the lower roll I2 and henceare worked thereby. This results in the surface ll of the raised portionl'l retaining its original color and texture, this usually being acomparatively dull surface contrasting with the relatively smooth, shinysurface of the nonraised, worked parts of the embossed design. Thiscontrast between the shin nonraised parts and the relatively dullsurface of the unworked raised parts of the embossed design imparts adistinctive appearance to the embossed sheet.

The embossing operation on the sheet area S results in the latter beingelongated in the direction of the path of travel of the sheet S throughthe rolls 1 I, I2, this path of travel being indicated by the arrow inFig. 1. I have discovered that the unembossed area S must be elongatedsimultaneous with and to the same extent as the elongation of theembossed area S" if wrinkles and other distortions of the sheet S are tobe avoided. This elongation of the unembossed area S is provided by therolling or reducing portions H, l2 of the rolls l I, IE, it being notedthat these rolling portions comprise the remaining surface areas of therolls to the left of the embossing surfaces H", [2".

As shown in Fig. 2, the sheet S is of uniform thickness before beingpassed through the rolls.

'l-Iowever, during the localized embossing operation of the sheet areaS, the unembossed sheet area S is reduced in thickness by the rollingportions l I, [2' of the rolls, as shown in Figs. 3 and 4. Thisreduction in thickness must be of a predetermined extent which willcause the unembossed area S to be elongated in a longitudinal directionto the same extent that the embossed area S" is elongated as a result ofbeing worked by the embossing operation. Since it is contemplated thatthe method and apparatus of the present invention be applied to theembossing of various types of sheet material, including textile fabric,paper, metal and plastic, no definite data can be given as to thenecessary reduction of thickness of the unembossed area S. However, itwill be obvious that by simple experiment with the particular materialto be embossed, there can be readily determined the elongation resultingfrom the embossing of the sheet area S and hence also the necessaryelongation of the unembossed area S that must be produced by the rollingportions 5 I, 12' of the rolls.

The wavy configurations [8 of the sheet S, as shown in Figs. 3 and 4,are produced by conventional coining elements on the embossing surfacesl l l2 of the rolls, this coining operation occurring simultaneouslywith the above noted embossing and rolling operations.

It is to be understood that the specific apparatus and method shown inthe drawing and described in the specification are intended to be merelyillustrative of one of the many forms which the invention may take inpractice and are not intended to limit the scope of the invention, thelatter being delineated in the appended claims. The term sheet includes,of course, strip material in any desired width and length.

Having described our invention, what we claim and desire to secure byLetters Patent is as follows:

1. An apparatus for roller embossing a localize-zl area of continuoussheet material, said apparatus comprising a pair of rolls, means forrotatably mounting said rolls, and drive means for rotating the rolls,each of said rolls being provided with a pattern for embossing alongitudinal area of a sheet of material passed between the rolls, meansfor reducing the thickness of the remaining unembossed area of saidsheet so as to elongate said remaining area to the same extent as theelongation resulting from the embossing thereof of said embossedlongitudinal sheet area, a surface area of one of said rolls beingprovided with embossing proj actions and the surface area of the otherof said rolls being provided with recesses each receiving a respectiveone of said projections, the clearance distance between the outermostface of each of said projections and the bottom of its respective recessbeing greater than the clearance distances between the other oppositeadjacent non-embossing portions of the rolls, whereby a clearance spaceis provided between the sheet material being embossed and the bottoms ofthe recesses.

2. An apparatus for roller embossing continuously localized areas of a.continuously moving sheet, said apparatus comprising a pair of rolls,means for rotatably mounting said rolls, and drive means for rotatingthe rolls, each of said rolls being provided with a pattern forembossing longitudinal areas on said moving sheet passed between saidrolls, means for reducin the thickness of the remaining unembossed areaof said sheet so as to elongate said remaining area to the same extentas the elongation resulting from the embossing thereof of said embossedlongitudinal sheet area, a surface area of one of said rolls beingprovided with embossing projections and the surface area of the other ofsaid rolls being provided with recesses each receiving a respective oneof said projections, the clearance distance between the outermost faceof each of said projections and the bottom of its respective recessbeing greater than the clearance distances between the other oppositeadjacent non-embossing portions of the rolls, whereby a clearance spaceis provided between the sheet material being embossed and the bottoms ofthe recesses, the clearance ldistances between the sides of theprojections and the respective opposite adjacent sides of the recessesbeing greater than the clearance distances between the other oppositeadjacent non-embossing portions of the rolls, whereby a clearance spaceis provided between the sheet material being embossed and the sides ofthe recesses.

3. An apparatus for roller embossing continuously localized areas of acontinuously moving sheet, said apparatus comprising a pair of rolls,means for rotatably mounting said rolls, and drive means for rotatingthe rolls, each of said rolls being provided with a pattern forembossing longitudinal areas on said moving sheet passed between saidrolls, means for reducing the thickness of the remaining unembossed areaof said sheet so as to elongate said remaining area to the same extentas the elongation resulting from the embossing thereof of said embossedlongitudinal sheet area, a surface area of one of said rolls beingprovided with embossing projections having a horizontal flat surfacesand the surface area of the other of said rolls being provided withrecesses each adapted for receiving a respective one of the projectionfiat surfaces in contacting relationship, the clearance distancesbetween the sides of the projections and the respective oppositeadjacent sides of the recesses being greater than the clearancedistances between the other opposite adjacent nonembossing portions ofthe rolls, whereby a clearance space is provided between the sheetmaterial being embossed and the sides of the recesses.

FREDERICK A. SUNDERHAUF. JAMES C. OHEAR.

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